Coupling for cables



Jan. 6, 1948. L.. G. BRAzxER x-:T AL

COUPLING FOR CABLES Filed May 1e, 1944 Patented Jan. 6, 1948 UNITED STATES COUPLING FOR CABLES Leslie Giddens Brazier and Douglas Taft Hollingsworth, London, England, assignors, by mesne assignments, toV British Insulated Callenders Cables Limited, London, England, a company of Great Britain Application May 16, 1944, Serial No. 535,802 In Great Britain April 30, 1943 Section 1, Public Law 690, August 8, 1946 Patent expires April 30, 1963 6 Claims. (Cl. 174-94) This invention relates to a coupling for application to the end of a cable formed of wires of ductile metal, for instance aluminium or copper, comprising a sleeve or socket (hereinafter referred to as a sleeve) of ductile metal within which the wires are gripped by forcing in the wall of the sleeve so as to compress the wires out of their normal shape. Such a coupling is reierred to herein as of the compressed sleeve type. The coupling to which the invention applies is for use with a type of cable in which the wires are stranded as a hollow cylinder enclosing a separate centre part which is not carried into and through the coupling. In such a case the wires, when bunched together for insertion in the coupling sleeve, form a group of substantially smaller diameter than when they lie in their normal positions in the cable. An object of the invention is to provide a coupling for such conditions which avoids the production oi a place of weakness in the cable just outside the sleeve.

In the improved coupling the space of truncated conical form lying within the wires as they are brought down from the diameter which they occupy in the cable to the diameter which they occupy in the coupling sleeve is taken up mainly by a ller block shaped to t within the space and having a rounded end adjacent the coupling.

This ller block is connected with a rod which extends from the block axially and passes through the bunch of wires and is held there. By this rod the block is secured in the correct relation to the mouth of the sleeve. Its rounded end then lies a short distance axially outside the mouth of the sleeve and this mouth is rounded off. The arrangement thus provides that the wires are held between the mouth of the sleeve and the filler block with suicient rmness to prevent undue flexing of the wires.

' ures of which show in longitudinal section three The block is necessarily inserted in place before the wires are brought down to the smaller diameter and bunched for insertion in the sleeve. The adjustment of the position of the iiller block longitudinally is carried out before the wall of the sleeve is compressed. When this operation takes place it forces the wires within the sleeve to press upon the rod and bite into the rod, if of ductile metal, and hold the rod and thereby hold the block in the position into which it has been adjusted relative to the sleeve so that the support of the wires given by the block is maintained.

The invention will be further described by the examples.

Figure 1 shows a permanent joint between two lengths of cable;

Figure 2 shows a joint between a length of cable and a terminal member; and

Figure 3 shows a disconnectible joint which may be applied to two lengths of cable.

In each of these cases the cable to be coupled comprises a centre part l surrounded by a, ring of wires 3 which is enclosed in a flexible covering 4, for instance of rubber or of rubber rein? forced with canvas. The centre I may consist of lengths of flexible material, such as cellular rubber 30, alternating with discs 3l of more rigid material, such as wood, covered by a tubular skin 32 of rubber. This centre part terminates at the point 2 and the wires 3 are gradually brought inwards and bunched together to form a group to lie within the coupling sleeve. This arrangement provides that there is a space of approximate truncated conical form between the point 2 where the centre part of the cable ends and the region Where the Wires are bunched together. In accordance with the invention this space is occupied by block 5 of rigid material, for instance wood, which is engaged by a rod 6 and held in place thereby. The engagement between the rod 6 and the block 5, in the examples illustrated, is effected by passing the rod 6 through a central longitudinal hole 'l in the narrower end of the block and screwing it into a nut 8 which lies within a cavity 9 formed in the block and accessible irom one or both sides. This cavity is so dimensioned that, while the nut can be inserted readily from the side it cannot turn in the block. The end of the rod is threaded to engage the nut and is screwed thereinto after being passed into the hole 1.

In the permanent joint shown in Figure l, the two cable lengths to be connected are identical in structure and, as will be seen, the figure is symmetrical about a central vertical line. The coupling member is the sleeve l0. In making this joint the rst step is yto remove the outer covering of the wires from the end portion of each length of cable and to take out the end portions of the centre part oi each length of cable. The wires are then cut to the desired length and the filling block 5 with the rod 6 in position is inserted in the cable end. This rod 6 is screw-threaded at its outer end. The ends of the wires 3 are then closed round the rod 6, being bunched together. into a compact cylinder. In

aid of the accompanying drawings, the three gdoing this the two layers of Wire, which are found ,on to the wires.

in the cable, have to be rearranged so as to make a greater number of layers to occupythe space round the rod 6- and lform a cylindrical group which will be a good fit within tl`e"`endof the sleeve I. In the drawing 5 layers are shown in the bunch.

After the wires have been arranged: as"de"" scribed, they are held in position by temporary clips; one placed so as to have its 'frontedgl'e at" the line II at which the sleeve `Iii"willtermin'"te" and-th'e'end of the rod 6 is out off flush with the when in final position and one o'r'rore between this point and the end of the wires'. Oveth'en end of the rod 6, which projects from the bunch of v` wires, is now applied a washer? l-Z" and I3 is screwed on to the end of the rod. The nut" is tightened up so as to draw forwardthel-rod 6- with the block 5 until the latter occupies the'po-` sition shown in the drawing in relation to the line I I. After this has been done the clip'n'ealest the end of the bunch of wires is removed and the sleeve Ii] is` pushed' over this end and ad'-vr vanced towards the line I I. During thisadvanc# ing any intermediate clip or clips whichbrnay have been provided is or are remov'edan'd'nally the sleeve is brought into or near the position shown in the drawing onf one endf of cableisay the end shown at the left-hand side ofthe' dra-wing. The clip at theA line II is then'removedi The sleeve I when applied has a smoothl oylindrical surface, both internally and externally; After application to the bunch' of wires it is caused to grip these wires by having a numbr'off cir-- cumferential grooves forcibly pressed 'in' itsf outer surface so as' to produce a series? of local 'reduc'-A tions of thediameter of'the insideof the 'sleevi This is accompanied by a` co'mpacti'ng'of the'bunch of wires by forcing the individual wiresfout of their circular shapeinto some more o'r'le'ss'po'- lygonal form' in cross-section; therebysubs'tanf-j tially eliminating the interstices"between* the wires; One manner in which'` thisfinayfbe done is described in the specication of application No; 515;?,24 for a patent of the United' Stat'esf'f America. During this process'pf consolidation the wires are'caused togrip therod 6' and'there"-I by ensure its retaining its position' and holding the block 5in place' without-`assistanoe'froritth nut I3.

After this' attachment of the'slee'v'e VIlltobne cable end the process can be repeated forv tHe1s'ec'-- ond cable end' so that iinally thefresulting'joilit indicated-in Figure 1 is attained; The cablejoint willgenerally be completed by the" appllcation of an appropriate covering of insulating' material; but this has'not been shown as it forins nc part of the present invention.`

It will be' seen thatvv in the nal" positio's all the parts of the'wires at'tlie mouthso'f thbsleeve' I are held in position between this sleve and the rounded end of the a-djaceritlblo'ckfs 5f'a'nd areY thereby supported so' that any substantial concentration of bending" at tl'ii'spint`is-prvented. TheV coupling arrangementshownin-Figl ure 2 is the same as that shown-in Figui -1`r as far as the left-hand" half ofthe 'figure i`sc n# ce1-ned. rThe coupling' sleeve I 4 ter'minatesinia reduced'screw-threaded end I5: Accordingly-tlie rod 6 is made of such a length that'it extends'fnot only through the bunched wires within the sleeve I4, but also through the central bore;inf-th'fePie` duced end I'of'this sleeve.r The'iinal pullingn of the block into positionbythe`rodf6"is"ciried out after the sleeve i4 hasbeen'slippedfoveif'the bunched wires and before tne'slf'aeveis pressed This pulling' up .is Adone by a end Voi the part I5.

secured inpo'siti'on by the grub screw Il.

Vpaft'lElservesa'sa terminal member to which can The socket member I6 is their screwedA over the reduced end part I5 and This be'connectedbythe bolts IB any desired part, for instancea socket shown at I9.

T"facil itat the fitting of the sleeve I4 over tl'ebun'ched Vwires and to secure good contact betweent'heindividual wires and between the wires andthesleeve the bunched wires are coated with petroleumV jelly, or similar lubricant. The hole 20i'sp`ovided in the sleeve I4 to permit the escape of surplus lubricant during the compression of the-"sleeve and the accompanying consolidation ofthe wires.

The coupling shown in Figure 3 provides' two similar' half-couplings for the adjacent ends of cable lengths and a third coupling member by which the' end parts of these'two halfecouplings arey releasably joined together. The coupling sleeves 2I and' 22 have reduced end-portions; 23 andi 24 respectively. The attachment of the cable end t'o'ea'chA of these sleeves 2| and' 22 is carried out in the way describedv in connection' with'Fig-- ure 2; the' nuts being removed fromI the rodsr andthe ends of thesel rods" beingcut off flush with the ends of the reduced portionsl 23 andL 24'; The'joiningtogether' of the two'lengths of cable iseffected by means of the screw-threadedl sleeve 25. The end 23of the sleeve 2I' hasa lefthand thread and the end 24 of the sleeve 22 has'a right# hand thread andthe twohalves of the-sleeves 25 are correspondingly threaded so that rotation-'of the sleeve relative to the two cable ends'draws these endstogether into triennal-position shown in Figure 3;' For this rotation thesleevef25fmay be engaged by a Spanner on flats shown at v26: The sleeve maybe' secured infpositionby grub screwsfZ'Il.

What we claimasour invention ist lpAwmethodof making a cablevjoint'usingra couplingof'the compressed sleeve type for vthe conductor of an'electric cable ofthe kindin'which the wires forni a hollow cylinder round a sepa; rate centre part, comprisinginserting a conoidal lling block` with a rod extending-axially therefiomin the space within the wires, closing the wiresdownroundthe block and rod tolle closely ontl'ie` rodI with'` tner diameter overthe wires Substantially' smaller lthan4 in` theV cable; drawing the block endvvise into position by nia'nipulatingd an end 'of therod which' projects' beyond the ends of the wires, applying the coiipling'sleev over' the wires4 androdv uptorthe neighbourhood of'V the endof'the block butno't ov'el" theblock and coni: pressing' the saidsleeve and'thereby' consolidating the hunched WiresandcauSing them togrip and holdthe rod. V

2; A"y method of making a' cable joint using a coupling' of-th'e compressed sleeve'type for the` conductor of an1 electric cable of the kindin wh'i'ohTthe-vfire's form a hollow cylinder yround a separatelcentre part,r comprising inserting a' co; noida'l filling block with arodv extending axially thereffromintlie spacewithin thewires, closing the wires down round the block and rod to'lie closely on the rod with the diameter' over" the wires'f'substanti'ally smaller than-inthe cable, ap;A

'plying temporary clips round the wires where they are closed down round the rod, then drawing the block endwise by manipulating an end of the rod projecting beyond the ends of wires, then removing the clips progressively starting from the ends of the wires and at the same time applying the coupling sleeve over the wires and rod up to the neighbourhood of the end of the block but not over the block, then compressing the sleeve and thereby consolidating the wires within it and causing them to grip and hold the rod.

3. A method of making a cable joint using a coupling of the compressed sleeve type for the conductor of an electric cable of the kind in which the wires form a hollow cylinder round a separate centre part, comprising inserting a conoidal filling block with a rod extending axially therefrom in the space within the wires, closing the wires down round the block and rod to lie closely on the rod with the diameter over the wires substantially smaller than in the cable, inserting the rod with the wires closed down round it into the coupling sleeve so that the sleeve is near to but does not cover the conoidal block and so that an end of the rod projects beyond the wires and the outer end of the sleeve, drawing the block enclwise into position by manipulating the projecting end of the rod and compressing the sleeve thereby consolidating the bunched wires and causing them to grip and hold the rod.

4. In a cable joint embodying a coupling of the compressed sleeve type for the conductor of an electric cable of the kind in which the wires form a hollow cylinder round a separate centre part and the centre part terminates before the coupling and the wires are bunched together to a smaller diameter for insertion in the coupling I sleeve, a conoidal lling block lying within the ring of wires and between the end of the centre part of the cable and the bunched wires and outside said sleeve and a rod engaging the said block and extending through the bunched wires and held therein by the compression of the sleeve thereby securing the said block in supporting position for the wires at the mouth of the sleeve.

5. A cable joint, embodying a coupling of the compressed sleeve type, between two lengths of an electric cable of the kind in which the wires form a hollow cylinder round a separate centre part and the centre part terminates before the coupling and the wires of each of the two lengths are bunched together for insertion in opposite ends of a coupling sleeve, the said joint comprising in each cable end a conoidal lling block lying within the ring of wires and between the end of the centre part and the bunched wires and outside said sleeve, a rod engaging the said block and extending through the bunched wires with a screwed end projecting beyond them and a nut on said end and a sleeve surrounding the two sets oi' bunched wires and the rods and nuts and gripping and holding the said parts as the result of the compression thereof.

6. A cable joint, embodying a coupling of the compressed sleeve type, for the conductor of an electric cable of the kind in which the wires form a hollow cylinder round a separate centre part and the centre part terminates before the coupling and the wires are bunched together to a smaller diameter ior insertion in the coupling sleeve, the said joint comprising a conoidal lling block lying within the ring of wires and between the end of the centre part of the cable and the bunched wires and outside said sleeve, a rod engaging the said block and extending through and beyond the bunched wires, a coupling sleeve having in its length a compressed part and an uncompressed part, the wires and rod lying within the compressed part and being held thereby and the projecting end of the rod passing through the uncompressed part for the full length thereof.

LESLIE GIDDENS BRAZIER. DOUGLAS TAFT HOLLINGSWORTH,

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,973,322 Staples Sept. 11, 1934 1,980,426 Noyes Nov. 13, 1934 2,239,026 Wagner Apr. 22, 1941 943,168 Shufflebottom et al. Dec. 14, 1909 FOREIGN PATENTS Number Country Date 194,851 Great Britain Mar. 22, 1923 

